Package org.apache.beam.sdk.io.gcp.spanner.changestreams.action

Class HeartbeatRecordAction

  • public class HeartbeatRecordAction
extends java.lang.Object
    This class is part of the process for ReadChangeStreamPartitionDoFn SDF. It is responsible for processing HeartbeatRecords. The records will be used to progress the watermark for the current element (partition).

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.util.Optional<org.apache.beam.sdk.transforms.DoFn.ProcessContinuation> run​(PartitionMetadata partition, HeartbeatRecord record, org.apache.beam.sdk.transforms.splittabledofn.RestrictionTracker<TimestampRange,​com.google.cloud.Timestamp> tracker, org.apache.beam.sdk.transforms.splittabledofn.ManualWatermarkEstimator<org.joda.time.Instant> watermarkEstimator)
      This is the main processing function for a HeartbeatRecord.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • run

        public java.util.Optional<org.apache.beam.sdk.transforms.DoFn.ProcessContinuation> run​(PartitionMetadata partition,
                                                                                       HeartbeatRecord record,
                                                                                       org.apache.beam.sdk.transforms.splittabledofn.RestrictionTracker<TimestampRange,​com.google.cloud.Timestamp> tracker,
                                                                                       org.apache.beam.sdk.transforms.splittabledofn.ManualWatermarkEstimator<org.joda.time.Instant> watermarkEstimator)
        This is the main processing function for a HeartbeatRecord. It returns an Optional of DoFn.ProcessContinuation to indicate if the calling function should stop or not. If the Optional returned is empty, it means that the calling function can continue with the processing. If an Optional of DoFn.ProcessContinuation.stop() is returned, it means that this function was unable to claim the timestamp of the HeartbeatRecord, so the caller should stop.

        When processing the HeartbeatRecord the following procedure is applied:

        1. We try to claim the heartbeat record timestamp. If it is not possible, we stop here and return.
        2. We update the necessary metrics.
        3. We update the watermark to the heartbeat record timestamp.